The increased availability of high-resolution imagery in the scientific and intelligence communities has led to an increased demand for displays capable of rendering such imagery. Conventional flat-panel displays are commonly available at resolutions up to 1600×1200 pixels, with a few displays (such as the Apple Cinema HD and IBM 221T) offering greater resolutions (2560×1600 and 3840×2400, respectively). Nonetheless, even the highest resolution single displays remain inadequate for close-in, immersive viewing of extremely high-resolution imagery.
A method of combining less expensive component displays into a large, high-resolution display would be advantageous for workstations such as those used in the intelligence and scientific communities. Abutting component displays one aside another in a tiled manner is a simple and convenient approach, but the bezel surrounding each component display does not allow for the seamless display of a single high-resolution image across the component monitors. Overlapping the bezels is possible if some component displays are positioned in a plane forward of the plane containing the remaining displays, but the resulting offset between adjacent displays interferes with the illusion of a single large display.
Gesture recognition against a changing background is known, as gesture recognition technologies are highly useful for manipulation of virtual objects and desktops. Recognition using visible light cameras is difficult, however, as accommodating the changing contrast associated with projected backgrounds is computationally expensive and unreliable. One solution is to use infrared light. Any active infrared illumination is invisible to the human eye, and the IR-sensitive camera receiving the reflected light is not affected by the projected background (assuming the visible light projector has a filter to block IR from being emitted). Infrared detection may be passive, such as a system that uses an IR camera to detect the temperature difference between a user's arm and the tabletop display. One example of a passive infrared system is disclosed by Koike et al. (Integrating Paper and Digital Information on EnhancedDesk: A Method for Realtime Finger Tracking on an Augmented Desk System, ACM Transactions on Computer-Human Interaction, Vol. 8, No. 4, December 2001, Pages 307-322). Other systems use active IR sources to illuminate a diffuser or other projection surface from the same side as an IR-sensitive camera, so that a user's hand or other object held on or near the surface reflects IR back to the camera. Sony's HoloWall and HoloTable use this method to detect gestures when a hand is between 0 and 30 cm from the surface, depending on the threshold setting.